From German patent 12 45 371, the obtainment is known of cyclohexanone-oxime by means of the catalytic reaction in the liquid phase of cyclohexanone with NH.sub.3 and H.sub.2 O.sub.2 (ammoximation reaction), at 5.degree.-40.degree. C., in the presence of a catalyst constituted by phosphotungstic acid, or by similar compounds. This type of catalyst, however, is difficult to handle, above all during the step of separation of the product from the catalyst, and European patent publication 208 311 teaches an efficacious alternative route, constituted by the catalysis with a titanium-silicalite, of the type disclosed, e.g., in U.S. Pat. Nos. 4,410,501 and 4,480,135 and in European patents 132 550, 190 609 and 200 260. A particular type of post-treatment with H.sub.2 O.sub.2 of the titanium-silicalites (or of zirconium-silicalites) can endow them with exceptional and quite surprising catalytic properties in the reaction of ammoximation of various carbonylic compounds (see European patent application 87/108,577). A disadvantage of the heretofore used technique is however the need of providing, upstream an ammoximation facility, at least two further synthesis facilities, and namely:
a facility for cyclohexanone synthesis, generally by cyclohexaol dehydrogenation in the gas phase, also comprising an efficacious distillation section, in order to separate cyclohexanone from unreacted cyclohexanol;
a facility for the synthesis of hydrogen peroxide, which usually requires the presence of a (more or less hydrogenated) antraquinonic vehicle, a high hydrogen consumption and a complex series of operations.
The Applicant has now surprisingly found that the need of a facility for the ketone production from its corresponding alcohol, as well as of a separate facility for the H.sub.2 O.sub.2 production from H.sub.2 and O.sub.2 can be overcome at all, the complexity of the operations being drastically reduced.